<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>定时器的进度条</title>
    <style>
      .loading {
        width: 100%;
        height: 100%;
        position: fixed;
        top: 0;
        left: 0;
        z-index: 1000;
        background: #fff;
      }
      .loading .pic {
        height: 64px;
        width: 64px;
        background: url(img/35.gif);
        position: absolute;
        top: 0;
        bottom: 0;
        left: 0;
        right: 0;
        margin: auto;
      }
      img {
        margin-bottom: 30px;
        margin-left: 5vw;
        height: 90vh;
        width: 90vw;
        display: block;
        border: 3px solid #000;
      }
    </style>
    <script type="text/javascript" src="js/jquery.js"></script>
    <script>
      $(function() {
        var loading = '<div class="loading"><div class="pic"></div></div>';
        $("body").append(loading);
        setInterval(function() {
          $(".loading").fadeOut();
        }, 3000)
      })
    </script>
  </head>
  <body>
    <div class="box">
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading01.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading02.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading03.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading04.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading05.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading06.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading07.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading08.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading09.jpg?raw=true" />
      <img src="https://github.com/CruxF/IMOOC/blob/master/ProImages/ImgPreloading10.jpg?raw=true" />
    </div>
  </body>
</html>